Building Information Modelling (BIM)

Modelling is nothing new in the construction world. Architects, Structural Engineers and Building Services Engineers have been using 3D modelling for the last 25 or so years in some form or another.

It is the Building Information part of the process that has recently been brought to the fore, by the Government’s Construction Strategy released in 2011. This states that all Government funded projects will incorporate BIM level 2 by 2016, with an anticipated, nay expected, 20% reduction in construction cost and a similar reduction in carbon. There are currently three projects for the Ministry of Justice that are using the process to set the precedent.

So, we are now seeing some genuine pace to utilise the complete BIM process in the construction industry.

In addition, the current economic climate is making us think of new ways to reduce construction costs, whilst looking at the environmental issues. If the Government are willing to invest public money into the process, then we should expect others to follow suit.

Despite the new found drive to ensure the BIM process is taken forward within the UK we still lag behind other countries such as Denmark and Finland, where in 2007 the use of BIM was mandatory on all Government projects.

The concept; at the start of a project life the team works by inputting to a three dimensional building model which is developed through the design stage to tender.

The model can be used to generate a cost and programme plan, that can then be developed by the contractor into a set of installation drawings and developed further into a three dimensional computer model used for record drawing purposes.

The model will hold a register of the building components (assets) which can be easily transferred by inputting into an asset management programme, to be used through the building life cycle.

Colloboration at the highest level

It is widely recognised by those in the know, that BIM is a process that relies on the highest level of collaboration and has measurable benefits between clients, design consultants, PMs, cost consultants, contractors, facility managers and end users.

There are varying levels of the process to allow an understanding of the level of technical and collaborative working that will be required as well as tools, processes and techniques required.

Design consultants have been working at the level 1 and level 2 platforms for many years. Tools such as Revit and Cadduct are regularly used on projects to assist design teams with clash detection analysis and the IES and TAS software tools provide environmental modelling, which allow detailed space planning in a three dimensional form and clients gain detailed visualisations of buildings prior to construction.

The challenge

The challenge today is to ensure that the information regularly produced on projects at level 2 is further developed to provide real time cost and programme planning on a project, with the BIM model being ultimately used as a platform for the production of an asset management model to be utilised throughout the lifecycle of the building.

The success of utilising BIM on a project is to ensure the process is managed, supported and used by all parties throughout the project cycle and building life, to successfully use BIM it needs to be valued as the ‘heart of a project.’

BIM is suitable for use on new-build projects, capital net savings on construction costs have been recognised on new-build refurbishment projects, these figure exclude any cost savings realised through the use of an asset management programme for post occupancy.

Typical benefits of the BIM process include:

Early analysis of different design options to see best value whilst maintaining the most sustainable solution

Cost effective design solutions produced using the latest generation modelling techniques and tools

Reduction in risk as the design solutions are included in the virtual model, allowing all project team members to co-ordinate and arrive at the appropriate overall solution, which the client can actually see and influence accordingly to ensure expectations are met

Project delivery is reduced as the models are used to review the most appropriate construction methods and logistics as well as looking at complex issues and clash detection avoidance

Construction and operational safety risks are reduced by the use of the model to analyse the most suitable solution, including the ability to assess people movement and time taken to evacuate

Right first time approach is a reality with the modelling as co-ordination takes place at design, ensuring design is not modified at construction stage, with the consequential impact of time and money

Waste during the construction phase is reduced as the quantities can be more accurately taken direct from the model, and the programming capability allows for deliveries timed to minimise damage whilst stored on site

Lifecycle asset management with real data attached to the model. This includes the operation and maintenance activities required, parts and methods of shut down, disassembly and restart as required

Ongoing operational monitoring and improvement during the life of the building, allowing the design data to be compared to operational data with subsequent corrections or improvements to keep the operational costs as low as possible

There are clear gains to be had for clients who adopt a BIM approach and research suggests that these gains are demonstrable.

Up to 40% elimination of unbudgeted change.

Up to 80% reduction in time taken to generate a cost estimate

Cost estimation accuracy within 3%

Savings of up to 10% of the contract value through use of clash detection software

Up to 7% reduction on project time.

The BIM process is looking to shake up the whole construction process with early engagement and openness in a totally collaborative world.

Will it be successful? we believe so.

In a simplified explanation the BIM levels are as follows:

Level 0

Unmanaged CAD, most likely to be 2D CAD, with exchange via electronic or paper (The majority of projects are still using this level).

Level 1

Managed CAD in 2D or 3D format. 3D has been used increasingly for RIBA stages C and D for visualisation of the finished product to the client. This is also widely used by contractors for checking proposed designs against the other building elements. This level uses management processes to sit alongside design to minimise waste and general inefficiencies, which would affect the programme and cost.

Level 2

Managed 3D with the production of the model being progressed by all members of the project team. The models need not coexist in a single model, but the individual models should be developed in a logical manner to allow use by another party or subcontractor. This level embraces the collaborative working philosophy of BIM and may incorporate 4D programme and 5D cost elements.

Level 3

Fully open process and data integration enabled by IFC/IFD. This level has the model managed by a collaborative model server. This requires software interoperability and is also known as integrated BIM (iBIM). Level 3 facilitates design analysis on environmental performance at an early stage, health and safety aspects associated with construction and maintenance to be analysed in parallel with design, iBIM also looks at asset management throughout design to be part of the soft landings approach. This level brings in the 6D facilities management level to the process.